Abstract

Andreev reflection in contacts between a low-temperature superconductor(Pb or ) and the manganite (LCMO) is investigated. In the majority of cases behavior typical of superconductor/half-metallic ferromagnet contacts is observed: an excess voltage and suppression of the contact conductance in the region of voltages , where is the energy gap of the injector. However, some of the contacts demonstrate an increase of the conductance and an excess current on the current–voltage characteristic of the contact at . The character of the curves observed for those contacts corresponds to Andreev spectrum of a superconductor with an energy gap much larger than the injector gap . It is assumed that in contacts of the latter type, specific conditions prevail whereby the penetration of Cooper pairs into the manganite from an electrode with a singlet order parameter induces in the surface region of the manganite a superconducting state with a triplet type of correlations.